Telephone system.



' R. H. MANSON.

TELEPHONE SYSTEM.

APPLICATION FILED OCT. 9, 1907.

Patented D6G.5,1911.

3 vwawtoz UNITED STATES PATENT OFFICE.

RAY H. MANSON, OF ELYRIA, OHIO, ASSIGNOR TO DEAN ELECTRIC COMPANY, OF

ELYRIA, OHIO, A CORPORATION OF OHIO.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented. Dec. 5, 1911.

I Application filed October 9, 1907. Serial No. 396,534.

To all whom it may concern:

Be it known that I, RAYH. MANSON, citizen of the United States, residingat Elyria, in the county of Lorain and State of Ohlo, have invented acertain new and useful Improvement in Telephone Systems, of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification.

My invention relates to telephone systems, and has for its object theprovision of means for metering line calls automatically and without thepossibility of registering twice for any one call.

In some of the systems heretofore in use, especially where the meteringis controlled by the operators, double registration has occurred eitherthrough accidental displacement of the subscribers hook switch, orthrough accidental pressure on the operators controlling key. In allsystems controlled by the operators, moreover, time is consumed and theefficiency of the system is lowered by the extra work involved.

According to my present invention, I cause the circuit of a line meterto be completed when a connection is initiated by the operator, and themeter to be automatically actu: ated when the called subscriber hasanswered, the calling subscriber in the meantime keeping his line closedfor conversation. There is no special act to be performed by theoperator,v and after the meter has once been actuated, I cause thecontrolling device which brings about its actuation to be locked so thata second actuation is impossible until the answering plug is withdrawnfrom the line jack and replaced therein.

More specifically stated, the embodiment of my invention hereinafterdescribed comprises a meter for each subscribers line having itsmotor-magnet in series with the cutoff relay of the line, the circuitbeing nor-- mally incomplete at the line jack. When an answering plug isinserted in response to a call, this circuit is completed through aresistance to the main battery, but the meter does not operate. When thecalled subscriber answers, the calling subscribers supervisory relay inthe meantime remaining energized, a circuit is closed by bothsupervisory relays through a self-locking controlling relay, whichshunts the high resistance in the meter circuit, and causes theactuation of the latter. This controlling relay remains locked until theanswering plug of the pair haskbeen withdrawn from the calling line ]LCMy invention is illustrated in the accompanying drawing wherein- Figurel is a diagram showing two subscribers lines and an operators cordcircuit fol interconnecting them, together with line meters andcontrolling apparatus therefor. Fig. 2 is asimilar diagram showing amodified arrangement of the cord circuit.

Referring to the drawing and especially to Fig. l, A. and A are twosubscribers stations each connected by line wires 1 and 2 to a centraloflice, wherein the connective apparatus is typified by'a single cordcircuit marked 5- 678 with terminal plugs P and P. Each subscribersequipment contains the ordinary elements, comprising a transmitter T andreceiver T, hook H, ringer Q and condenser C. At the central office eachline has the usual line relay R controlling a lamp signal, and thecut-off relay R, which when a plug is inserted in a jack J, removes theline terminals from contact with terminals of the relay and groundreturn thereof, and places the line directly in connection with thespring jack, which may be multiplied if desired. In fact, this system isespecially useful in connection with multiple boards although notnecessarily limited thereto. In such a multiple equipment, the answeringjack J is provided with three contacts, while the multiple or callingjacks may have only two. The three contacts are marked in the drawing j,j and 1' Of these j and j are talking contacts and j is connected bywires 3 and 4t tot-he cut-off relay R and then to the motor magnet ofthe meter M and so to ground. Cooperating with the line jacks are theanswering plug P and the calling plug P. The latter performs no functionwhatever in connection with the meters, only those meters being operatedwhich belong to the calling lines. Each answering plug P, therefore, isprovided with means for completing the meter circuits so that the samemay be operated in due sequence.

The cord circuit may be briefly designated as a six-relay circuit,although by double winding, the actually separate relay units onlynumber four. These are S, S S

S of which S and S are double wound with their windings seriallyincluded in the battery bridge of each end of the cord. The doublewindings of these relays are used merely to balance the circuits, sincethe cooperating supervisory control relays S and S cannot be included inthe bridge but are in the separate local battery branches 29 and 10. Therelays S and S jointly control the flow of current from the battery B tothe supervisory lamp 8 associated with the answering plug P, while therelays S and S jointly control the circuit from the battery B to thesupervisory lamp 8 associated with the calling plug P. The single woundcontrol relays S and S become active as soon as the plugs P and P areinserted in the answering and calling jacks respectively, the circuit ofeach being completed through contacts 79 7' 3, R, i, M and ground. Theenergization of these control relays S and S cause the lamps s and s tobe connected to their respective branch wires 1112, the battery supplyto which is controlled by the double wound relays S and S which respondto current flow from the main battery B in the respective subscriberslines with which they are connected.

The relay S associated with the answering plug P is connected to batteryB through a resistance r, and since the magnets S, R and M are in serieswith the resistance, it is easy to adjust the same so that with no otherpath provided for the flow of current, the

latter will be too small to produce any effect on the comparatively lowwound magnet M which, moreover, has a certain amount of mechanical workto perform, calling for a larger current flow. The relays S and R,however, will function on the initial current flow through theresistance W. In order to operate the motor magnets M I provide anormally open shunt around the resistance r which closes in series twonormally open contacts controlled by the relays S and S respectively,and the self locking relay R This latter relay is of low resistance, andowing to its serial connection aforesaid, can only become excited whenboth supervisory relays are energized, that is to say, when current isflowing from the main battery B through the cord circuit to bothsubscribers lines. It will be observed that as soon as the relay R haspulled up, however, it closes a short circuit through itself around theresistance r and in parallel with the branch circuit controlled by thesupervisory relays S and S. By this means I prevent any false or doubleregistration, for since the relay B is looked as soon as the calledsubscriber A has answered (the subscriber A in the meantime keeping hisreceiver T off the hook) the meter circuit will remain closed that themotor magnet M will remain energized until the plug P is removed fromthe jack J. As an alternative and in order to permit recalling on thepart of the subscriber A without the necessity of pulling the plug Pwith each recall, I may provide the operator with a key at the pointindicated by a cross marked 00 in Fig. 1, so that the locking circuitmay be broken and the apparatus set for another operation. I do notconsider this advisable, however, since the underlying invention in thepresent case is to make the entire operation automatic and independentof the volition of the operator.

'Fig. 2 shows a modification in which the relay S not only controls theconnection of the supervisory lamp 8 to its branch wire 12, but alsocontrols the connection of the battery B to the relay B and its lockingcircuit as well as the circuit of the controlling relay S the cut-offrelay B and the meter magnet M. The idea in this is that since the plugP must remain in the answering jack J for recalls, and the plug P mustbe pulled in such cases for insertion in another wanted jack, the relay5 can, therefore, be employed to advantage to perform the same functionas the special key :rpreviously mentioned. In other words, if theoperator gets a recall from the subscriber A, she merely pulls thecalling plug P and having ascertained the new number wanted she sticksthat plug in the ack of the line called for and thus resets the metercircuit ready for a second operation. EX- cept for this operation, theshunt circuit around the resistance 1 is controlled in the same manneras before by both supervisories, with their contacts in series.

The operation of my invention thus described may be stated as follows:In the circuit of Fig. 1, assuming subscriber A is calling and hasremoved his receiver T from the hook H, which thereupon completes theline circuit 1 2, current flows through the line from the main batteryB, energizing the relay R and lighting the signal lamp associated withthe line jack J. The operator, perceiving this signal, inserts theanswering plug P and by means of the usual listening key (which is notillustrated) ascertains the number wanted. When the plug P is insertedin the jack J, a circuit is immediately completed, from the battery asfollows: B, 1.3, r, 14, S 29, 72 7' 3, R, 4, M and ground back tobattery. This brings the resistance r and the three magnets S R, and Min series with each other, whereby the magnet M will not be operated butthe other two will become effectively energized. The energization of therelay S connects its lamp 8 to the branch 11, and the energization ofthe relay R connects the line wires 1-2 to the jack springs j and jrespectively, at the same time disconnecting the relay R and its groundreturn, whereby said relay is deenergized and its lamp signal isextinguished. The lamp 8 does not glow at this step of theoperation forthe reason that the relay S becomes energized by current over thefollowing path: 7 7 7 7 7 7 2 j 7 7 .7 p7 7 9, S and ground back tobattery. Having ascertained the number wanted (which we will assume tobe that of subscriber A) the operator inserts the plug P in the jack Jof the wanted line. This causes the energization of the relay S and thecut-oif relay R of the Wanted line, over the following circuit: B, 13,18, S 10, p j 3, R, 4, M, and ground back to battery. In order toprevent the operation of the meter magnet M by the closure of thiscircuit, I either make the resistance of the relay S sufficiently highor I insert a limiting resistance the same as 1". Other means may beresorted to such as polarizing the magnets M and reversing the currentsupply through the calling and called ends, but I prefer the arrangementshown herein.

Having completed the connection, the operator proceeds to throw ringingcurrent on the line leading to station A in any ordinary or desiredmanner. In Fig. 1 I have not shown a ringing key as this is a matter ofcommon knowledge and necessity but in Fig. 2 I have indicated such akey. In practice, of course, every cord circuit must be provided withsuch a key or its equivalent, and we will assume the operator uses theringing key to call the subscriber A. When the subscriber answers,current will immediately flow through the supervisory relay S throughthe following path: B, 13, 7 S, v 2947 7 7 A: 1 p 7 a S, and ground backto battery. Relay S then becoming energized, opens the batteryconnection with the branch wire 12 thereby depriving the lamp 8 ofbattery current and causing it to become extinguished, the lamp circuitthus broken being traceable as follows: B, 13, 15, 21, 8 12, .9 22, sand ground back to battery. At the same time the relays S and S bothbeing energized act jointly in closing the following shunt circuit forthe resistance 1": B, 13, 23, R 24, s, 25, s 26, 14. This provides apath of reduced resistance for passage of current from the battery B tothe meter circuit,

. which is extended from the wire 14 as fol- M and ground back tobattery. The relay R will therefore remain locked, and the condition ofthe meter motor circuit will remain constant without regard to the condition of the supervisory relays until the plug I is finally withdrawnfrom the ack J.

\Vhen the subscribers have finished their conversation they hang uptheir respective receivers, thereby breaking their line circuits andthereby permitting the respective relays S and S to fall back, supplyingcurrent to the lamps s and s which by their joint glow indicate to theoperator a desire for disconnection. The operator thereupon pulls theplugs P and P breaking the local circuits 3l at the contacts j Thecut-oif relays R thereupon disconnect the lines from the jacks andreconnects the line relays R. The meter magnet M becomes deenergized,the cord circuit relays all lose current, including the locking relay Rwhich lets go its armature; and so all parts are restored to normalcondition of disuse, ready for another operation.

The cord circuit of Fig. 2 may be sub stituted for that of Fig. 1without change, and the operation is identical except that the relay Bmay be restored by merely pulling the plug P, so that if the subscriberA wishes to make a number of calls, he may do so and each call will beautomatically registered, the relay B being restored each time andprepared for the next call by the act of the operator in pulling theplug P.

I am aware that many changes and substi tutions may be made in thecircuits I have described, and many changes may be made in theapparatus, without departing from the spirit of the invention. Theforegoing description and the illustration accompanying it are thereforeto be taken as specific for purposes of explanation but not ofillustration. The ordinary four relay cord circuit may be employed ifdesired, although I consider the arrangement herein shown as preferable.All minor and non-essential changes and modifications are to beconsidered as clearly within the scope of the claims appended hereto.

While I have shown myv invention in the particular embodiment hereindisclosed, I do not, however, limit myself to this construction, butdesire to claim any equivalent modification that will suggest itself tothose skilled in the art.

Having thus described my invention what I claim and desire to secure byLetters Patent is:

1. In a measured service telephone system, subscribers lines,registering means at the central station connected therewith, anoperators cord circuit, a source of current connected to said cord, adevice controlled by the subscribers and associated with said cordcircuit for controlling the actuation of said meters, and means incircuit with the actuating winding of the registering means forpreventing the accidental manipulation of said means.

2. In a measured service telephone system, subscribers lines,registering meters connected therewith, an operators 3wire cord circuit,a battery connected with said cord circuit, a high resistance in circuitwith the actuating winding of one of the meters and in series with saidbattery, a normally open shunt circuit around said high resistance, anda winding means in said shunt circuit for automatically closing saidshunt circuit in the use of the lines thereby operating said meter.

3. In a measured service telephone system, subscribers lines,registering meters connected therewith, an operators cord circuitincluding a battery, a high resistance in circuit with the actuatingwinding of one of the meters and in series with said battery, a normallyopened shunt circuit around said high resistance, relays automaticallyactuated in the use of the lines for closing said shunt circuit therebycausing said meter to register, and a locking winding in said shuntcircuit for keeping said shunt circuit closed.

4. In a measured service telephone system, subscribers lines,registering meters connected therewith, an operators cord circuit forinterconnecting said lines having calling and answering plugs andprovided with a battery, a high resistance in series with said battery,a normally open shunt circuit around said high resistance, meanscontrolled in the use of the subscribers lines for closing said circuitto actuate said meter, and a low resistance locking relay in said shuntcircuit adapted to maintain said shunt circuit closed until released bythe with drawal of the answering plug.

5. In a measured service telephone system, subscribers 3-wire circuitsprovided with cut-off relays, call registering meters in series withsaid cut-off relays, an operators cord circuit for interconnecting saidsubscribers lines comprising a battery, a high resistance in series withsaid battery, a normally open shunt circuit around said high resistance,a low resistance locking relay in said shunt circuit, and relayscontrolled by the subscribers for closing said shunt circuit to actuatesaid meter, said shunt circuit being kept closed by the actuation ofsaid locking relay.

6. In a measured service telephone system, subscribers lines,registering meters connected therewith. an operators cord circuitprovided with a supervisory control relay, a high resistance and abattery in series with the winding of said supervisory control relay, anormally open low resistance shunt around said high resistance, meansfor automatically closing said shunt circuit to operate said meter, andmeans for maintaining said shunt circuit closed.

7 In a telephone system, the combination of a calling and a calledsubscribers line, a meter associated with the calling line, an operatorscord circuit for interconnecting said lines, a circuit for said meter, apair of supervisory relays in said cord circuit, initially directlycontrolling contacts in said meter circuit and a self locking relaythereafter maintaining said meter irresponsive to further control bysaid supervisory relays.

S. In a telephone system, a plurality of subscribers lines and operatorscord circuits for interconnecting them, supervisory relays and metersassociated with the lines, and locking means in the actuating circuitsof such meters and associated with said cord circuits, together withmeans whereby said meters are initially controlled by the supervisoryrelays for single registering, and thereafter are available for furtheropera tion by said locking relays.

9. In a telephone system, a plurality of subscribers lines, metersindependent of the talking circuit at an exchange associated therewith,means for interconnecting such lines for conversation, a supervisoryrelay associated with such connecting means for each of the linesconnected thereby, and means jointly directly controlled by thesupervisory relays associated with the connected lines for bringingabout the automatic actuation of the said meters.

In witness whereof, I hereunto subscribe my name this 14th day ofSeptember A. D., 1907.

RAY H. MANSON.

l/Vitnesses T. A. CORNELL, A. J. ROBERTS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

